Mold for tube used in a loom for weaving carpets,especially axminster carpets



3,429,008 SPECIALLY Feb. 25 1969 H. BUD

MOLD FOR TUBE USED IN A LOOM FOR WEAVING CARPE'I'S, E

AXMINSTER CARPETS Sheet Original Filed Feb. 26, 1965 Inventor Hmvs 801) By Mk MA 44%:

Attorney Feb. 25. 1969 H. BUD 3,429,008

MOLD FOR TUBE USED IN A LOO OR W VING CARPETS, ESPECIALLY AXMINS CAR 8 Original Filed Feb. 26, 1965 Sheet 2 of 5 .7 Inventor VA HMS BUD y M 0 440 M A ttorney H. BUD 3,429,008 00M FOR WEAVING CARPETS, ESPECIALLY Feb. 25, 1969 MOLD FOR TUBE USED IN A L AXMINSTER CARPETS Sheet 3 of5 Original Filed Feb. 26, 1965 A Home y H BUD MOLD FOR TUBE USED IN A LOONi FOR WEAVING CARPETS, ESPECIALLY Original Filed Feb. 26. 1965 AXMINSTER CARPETS Inventor H M15 B By W a! M Attorney Feb. 25. 1969 I H D 3,429,008

MOLD FOR TUBE USED IN A LOOK R WEAVING CARPETS, ESPECIALLY AXMINSTER CARPETS Original Filed Feb. 26 1965 Sheet 5 -of 5 I nvenlor HIM/.5 BUD y W M W A Home y United States Patent 3,429,008 MOLD FOR TUBE USED IN A LOOM FOR WEAV- ING CARPETS, ESPECIALLY AXMINSTER CARPETS Hans Bud, London, England, assignor to English Numbering Machines Limited, Middlesex, England, a British company Original application Feb. 26, 1965, Ser. No. 435,615. Divided and this application July 18, 1966, Ser. No. 610,710 Claims priority, application Great Britain, Mar. 3, 1964,

8,842/64 US. Cl. 18-42 1 Claim Int. Cl. B2811 7/18, 7/10 ABSTRACT OF THE DISCLOSURE The invention discloses a mold for molding a fiat-walled plastic tube for use in a loom for weaving Axminster carpets. The mold comprises two mold inserts having recesses forming a mold cavity complementary in shape to the shape of the plastic tube, a blade the ends of which are held by two pairs of additional mold inserts adjacent opposite ends of the first mentioned mold inserts extends through the mold cavity as a core and is releasably held by spring means. At least one pair of projections extend into the mold cavity on opposite sides of the mold cavity and bearing against opposite sides of the blade to center the blade during molding. Ejector pins are provided which exclusively act on the ends of the blade and release the blade from the spring means on ejection.

This is a division of application Ser. No. 435,615, filed Feb. 26, 1965.

The invention relates to tubes for use in looms for weaving carpets, especially Axminster carpets.

Axminster carpet looms have a carrier provided with a series of metal members formed by flat metal tubes, each tube being wider at one end than at the other, the wide end being sloped relative to the tube axis, and the tube wall near the wide end being slotted for facilitating fixing of the tubes to the carrier. As is known, in use of the looms, tufting yarns are threaded through the tubes.

It is an object of the invention to re-design such tubes so that they can be easily manufactured of plastic material.

It is another object of the invention to provide such tubes made of plastic material which can easily be molded.

It is a further object of the invention to provide a mold for facilitating the manufacture of such tubes from plastic material by molding.

It is a more specific object of the invention to provide novel support means for a core of a mold for molding such tubes.

These and other objects and advantages will become apparent to those skilled in the art from the following detailed description of my invention when read with reference to the accompanying drawings, which are given by way of example and in which:

FIG. 1 shows in side elevation a flat-walled plastic tube for use in a loom for weaving carpets;

FIGS. 2 to 6 show views taken in cross section along the lines II-II to VI-VI, respectively, of FIG. 1;

FIG. 7 shows a plan view taken in section through a mold for molding the tube shown in FIG. 1;

FIG. 8 shows a view taken in cross section along the line VIIIVIII of FIG. 7;

FIG. 9 shows a view taken along the line 1XlX of FIG. 7;

FIG. 10 shows a partial section through the mold taken along the line X-X of FIG. 7;

3,429,008 Patented Feb. 25, 1969 FIG. 11 shows a side view taken in elevation of a modified form of the fiat-walled plastics tube;

FIGS. 12 to 16 show views taken in cross-section along the lines XIIXII to XVI-XVI, respectively, of FIG. 11;

FIG. 17 shows a view taken in section through parts of a mold for molding the plastics tube shown in FIG. 11;

FIG. 18 shows an end view taken in elevation of a plurality of mold parts for simultaneously molding a plurality of tubes such as that shown in FIG. 11;

FIG. 19 shows a plan view on a larger scale of one of the mold parts shown in FIG. 17;

FIG. 20 shows a view taken in side elevation of the mold parts shown in FIG. 19;

FIGS. 21 to 27 show partial views taken in section along the lines XXI-XXI to XXVIIXVII of FIG. 20; and

FIG. 28 shows a view taken in side elevation of on of the mold parts shown in FIG. 17.

The tube shown in FIGS. 1 to 6 is made of synthetic plastic material, and has two flat side walls 1 joined by a top wall 2 and a bottom 3, the bottom 3 being slightly inclined towards the top wall 2 along a part of the length of the tube. The top wall 2 is turned outwardly of the tube by a small amount at one end of the tube to form a lip 4, which serves to wedge the tube in position when the tube is mounted in a tube carrier (not shown) as described below.

Each of the side walls 1 is formed with a circular opening 5, and a rectangular abutment 6 and an end abutment 7, the two abutments 7 being formed at an end 8 of the tube, this end 8 being the end of the tube at which the lip 4 is formed and being wider than the opposite end of the tube. As can be seen from FIG. 1, the wide end 8 is sloped relative to the axial direction of the tube. On each side wall 1, the abutment 6 has an abutment edge 9 spaced from an abutment edge 10 on the abutment 7, in the axial direction of the tube, by a distance a corresponding to the width of a bridge member of the tube carrier on which the tube is mounted when in use, as described below. The abutment edge 10 extends over the entire width of the corresponding side wall 1, and the abutment edge 9 extends only across a part of the width of this wall and forms one edge of the rectangular abutment 6, which slopes and merges with the flat wall 1 on the other three sides thereof.

The mold for forming this tube, as shown in FIG. 7, has mold inserts 11 and 12 forming a mold cavity, and a blade 13 is movable into this mold cavity as a core, projections in the form of pins 14 and 15 extending from the mold inserts 11 and 12 into the mold cavity on opposite sides of the mold cavity for bearing against opposite sides of the blade 13 to centre the blade 13 during molding.

One end of the blade 13 is held between mold inserts 16 and 17, a pair of springs 18 being secured to the mold insert 17 by screws 19 for releasably retaining this end of the blade 13.

The other end of the blade 13 is held between mold inserts 20 and 21. Ejector pins 23 and 24 are slidable within the mold inserts 21 and 17 for ejecting the blade 13 on completion of the molding operation.

During the molding operation, plastics material is injected through a runner 26 (FIG. 9) into the space be tween the blade 13 and the two mold inserts 11 and 12. The injected plastics material does not flow evenly along both sides of the blade 13 and pressure differences are therefore liable to occur. The pins 14 and 15 engaging the opposite sides of the blade 13 prevent the blade 13 from bending under these pressure differences.

The plastic tube shown in FIG. 11 is similar to that shown in FIG. 1 and the same reference numerals have accordingly been employed to indicate the same parts in both of these figures.

However, instead of the circular openings 5 shown in FIG. 1 the side walls of the tube shown in FIG. 11 are each formed with an opening 30 which is generally rectangular when viewed in elevation and the bottom of which is defined by a surface 31 (FIG. 13) which is inclined relative to the side wall 1 to facilitate removal of the tube from its mold as described below. Also, instead of the abutment 6 of the tube shown in FIG. 1, the tube shown in FIG. 11 is formed with a smaller rectangular abutment 33 having more gradually sloping side walls 34 and 35 on two sides thereof. The abutment 33 has an abutment edge 36 extending across only part of the width of the tube, the abutment edge 36 being perpendicular to the axial direction of the tube and to the corresponding side wall 1, and the fourth side 37 of the abutment 33 is inclined to the corresponding side wall 1 but with a greater slope than the side walls 34 and 35.

FIGS. 17 and 18 show parts of a mold for molding the tube shown in FIG. 11. In FIG. 17, a blade 40 extends through a mold chamber 41 and is anchored at one end in mold parts 42 and 43 by means of a key 44.

As shown in FIG. 18, the mold cavity 41 is one of a plurality of such mold cavities, each of which is formed between an upper mold part 46 and two lower mold parts 47 and 48. The mold parts 42 and 43 are arranged to be moved to the right as illustrated in FIG. 17 relative to the mold parts 46 and 48 for withdrawing the blade 40 from between the mold parts 46 to 48 on completion of the molding operation. A pair of ejector strips 50 are arranged to slide longitudinally between the mold parts 47 and 48 for ejecting the molded tube therefrom after withdrawal of the blade 40.

As can be seen in FIGS. 19 to 28, each of the mold parts 47 and 48 is formed with a projection 51 projecting into the mold cavity 41. During the molding operation, the projections 51 contact opposite sides of the blade 40 for holding the blade 40 against bending. Each projection 51 is formed at one side with a sloping surface 52 corresponding to the surface 31 on the tube to facilitate ejection of the molded tube from the mold by the ejector strips 50.

The abutments 33 are formed by correspondinglyshaped recesses 54 in the mold parts 47 and 48, and the abutments 7 by correspondingly-shaped recesses 55 in these mold parts. The mold parts 47 and 48 are also provided with grooves 56 for receiving the ejector strips 50. During the molding operation, plastic material is introduced into the molding chamber 41 through a runner 57 formed in the mold part 46.

In use, the plastic tube is inserted into a tube carrier of an Axminster loom. Such tube carriers conventionally comprise a bridge member provided with a plurality of slots for receiving the tubes. With the tubes shown in FIGS. 1 and 11, the abutments 6 and 7 or 33 and 7 are spaced apart from each other in the axial direction of the tube by a distance a corresponding to the width of the bridge member of the tube carrier so that said bridge member can enter the space between these abutments. The lip 4 bears against, and is slightly resiliently deformed by, a part of the tube carrier, for example a spring member, for wedging the tube securely in position. The lip 4 also facilitates the entry of the yarn tufts into the tube.

The formation of the abutments on the flat walls of the tubes by molding, as described above, provides a convenient and cheap way of securing the tubes to the bridge member and avoids any necessity for forming slots in the tube walls in a separate manufacturing step. Moreover, the use of plastic tubes, which term as used throughout this specification embraces thermoplastic tubes and tubes of other m-oldable synthetic materials, has the advantage that when in use in carpet looms the knives of such looms are less liable to be damaged by contact with the present plastic tubes than with the metal tubes previously employed. Such contact may accidentally occur when damaged tubes fall from the tube carrier as the tuft yarn is fed through the tubes, or when the tube carriers are not properly gripped or located at the weaving station. Replacing the knives necessitates halting production on the looms, and regrinding of the knives is an expensive process. It is therefore advantageous to reduce damage of the knives to a minimum.

Plastic tubes are also less liable to be damaged while being threaded with the tuft yarn, and in transport and handling between this threading operation and mounting of the tubes on the looms. When metal tubes are used, such damage can cause sharp external or internal edges on the tubes. The external sharp edges tend to cut the threads which form the bases of the carpets, while the internal sharp edges cut the yarn which passes through the tubes, both of which can cause stoppage of the looms. Also, plastic tubes do not corrode.

It should be clearly understood that the specific embodiments described and illustrated are given merely by way of example and that many modifications, omissions and additions are possible without departing from the spirit of the invention.

I claim:

1. A mold for making a fiat-walled plastic tube for use in a loom for weaving carpets, the tube including an abutment near one end thereof, the abutment being arranged to bear against a tube carrier of the loom for attaching the tube to the carrier, said mold comprising a center pair of mold inserts forming a mold cavity between them, a first additional pair of mold inserts, spring means on one of the mold inserts of said first additional pair of mold inserts, a second additional pair of mold inserts adjacent the other end of said center pair of mold inserts, a blade movable into said mold cavity as a core, one end of said blade being held between the mold inserts of said first additional pair of mold inserts, the other end of said blade being held between the mold inserts of said second additonal pair of mold inserts, said one end of said blade being releasably retained by said spring means on said one mold insert, at least one pair of projections extending into said mold cavity on opposite sides of said mold cavity for bearing against opposite sides of said blade to center said blade during molding, and ejector pins arranged exclusively in mold inserts of said first and second additional pairs of mold inserts so as to act exclusively on the ends of said blade, at least one of said ejector pins being arranged in said one mold insert of said first additional pair of mold inserts so as, on ejection, to release said one end of said blade from said spring means.

References Cited UNITED STATES PATENTS 2,256,769 9/ 1941 Amrine. 2,301,338 11/1942 Smith. 2,439,906 4/1948 Piron. 2,604,661 7/1952 Karns. 2,822,578 2/1958 Lobell. 3,166,795 1/1965 Jotle. 2,688,159 9/1954 Swartz et al. 2,783,502 3/1957 Abplanalp 24963 2,994,921 8/1961 Hultgren. 3,167,817 2/ 1965 Zalkind. 3,183,292 5/1965 Dvoracek 18420 X 3,234,756 2/1966 Hanson 18-36 X 3,280,432 10/ 1966 Muller.

OTHER REFERENCES 579,752 8/ 1946 Great Britain.

J. HOWARD FLINT, 111., Primary Examiner.

US. Cl. X.R. 24963 

